SATA is a computer bus specifically for connecting mass storage devices to host systems. SATA stands for Serial ATA and is the follow-on interface to the PATA (Parallel ATA) interface originally designed in 1986.
The Serial ATA (SATA) interface was created in 2003 by the Serial ATA Working Group, which was later incorporated as a non-profit named the Serial ATA International Organization (SATA-IO).
The SATA interface was designed to be a much faster interface than PATA. Higher SATA speeds were arrived at by a much increased data rate on serial paired lines for transmit and receive.
The ATA/ATAPI basic interface commands used for the earlier PATA interface are supported by SATA to make the command set backward compatible.
|SATA Version||Maximum Performance||Highlighted Features|
|Initial SATA Launch|
|Backward Compatible with SATA 1.5 Gbits/sec|
|NCQ (Native Command Queuing|
Slimline/Micro Cables & Connectors
|Backward Compatible with SATA 3.0 Gbits/sec|
|mSATA (MO-300) Defined|
|m.2 (NGFF) Defined|
SATA Express Spec
The standard SATA connector found on 2.5” SATA SSD and Slim SATA (MO-297) are the same as shown above. There are a total of 22-pins broken into 7-pins for Data and 15-pins for Power.
The contact pads for these products is only found on one side of the connector. As you can see by the image, some pads are longer so they will make contact sooner when the connector is inserted. This is done to make sure the devices start up properly when hot swapping.
The detailed signal breakdown as used on the Cactus Industrial Grade SATA SSD are shown in the table below.
|S1 - Data||Ground||First to Contact|
|S2 - Data||A+||Host (Transmit +)|
|S3 - Data||A-||Host (Transmit -)|
|S4 - Data||Ground||First to Contact|
|S5 - Data||B-||Host (Receive -)|
|S6 - Data||B+||Host (Receive +)|
|S7 - Data||Ground||First to Contact|
|Coding Notch||Keys the Connector|
|P1 - Power||+3.3 V||3.3 V Source|
|P2 - Power||+3.3 V||3.3 V Source|
|P3 - Power||+3.3 V||3.3 V Source|
|P4 - Power||Ground||First to Contact|
|P5 - Power||Ground||First to Contact|
|P6 - Power||Ground||First to Contact|
|P7 - Power||+5.0 V||5.0 V Supply|
|P8 - Power||+5.0 V||5.0 V Source|
|P9 - Power||+5.0 V||5.0 V Source|
|P10 - Power||Ground||First to Contact|
|P11 - Power||Active LED||Activity LED|
|P12 - Power||Ground||First to Contact|
|P13 - Power||+12.0 V||12.0 V Source|
|P14 - Power||+12.0 V||12.0 V Source|
|P15 - Power||+12.0 V||12.0 V Source|
The mSATA (MO-300) uses a slightly different connector than the 2.5” and Slim SATA. There are a total of 52-pins, with 26-pins on each side of the circuit board.
Below is a detailed signal breakdown as used on the Cactus Industrial Grade mSATA SSD.
|Pin #||Assignment||Description||Pin #||Assignment||Description|
|1||N/A||N/A||27||Ground||Return Current Path|
|2||+3.3 V||3.3 V Source||28||N/A||N/A|
|3||N/A||N/A||29||Ground||Return Current Path|
|4||Ground||Return Current Path||30||N/A||N/A|
|8||N/A||N/A||34||Ground||Return Current Path|
|9||Ground||Return Current Path||35||Ground||Return Current Path|
|11||N/A||N/A||37||Ground||Return Current Path|
|13||N/A||N/A||39||+3.3 V||3.3 V Source|
|14||N/A||N/A||40||Ground||Return Current Path|
|15||Ground||Return Current Path||41||+3.3 V||3.3 V Source|
|17||N/A||N/A||43||Ground||Return Current Path|
|18||Ground||Return Current Path||44||N/A||N/A|
|21||Ground||Return Current Path||47||Reserved||N/A|
|23||Tx+||SATA Differential||49||DA/DSS||Device Activity/Disable Staggered Spin Up|
|24||+3.3 V||3.3 V Source||50||Ground||Return Current Path|
|25||Tx-||SATA Differential||51||Presence Detection||Pulled to Ground by Device|
|26||Ground||Return Current Path||52||+3.3 V||3.3 V Source|
To round out the Cactus SATA interface offering, we have CFast products which are defined by the CompactFlash Association and possibly a future M.2 (NGFF) form factor.
As always, if you need more information on the Cactus products to assist with a design, Talk to a Cactus Expert.